1. Field of Invention
The present invention relates to a passive electronic seal and, in particular, to a multi-secured method and device using RFID (Radio Frequency Identification) for security management, control and identification of transported goods and containers during transportation.
2. Related Art
Nowadays, 85% of global trading goods are transported through locked transportation containers; wherein the containers transited through sea transportation, duty-bonded trucks and freight trains are the main streams. Therefore, security monitoring mechanism for preventing transited goods from replacement or theft during transportation is a major issue to facilitate fast and smooth global trading. Currently, most of the anti-theft and anti-replacement designs still rely on conventional locking systems such as mechanical locks, spring locks and mechanic seal. These locking tools are printed with goods' serial numbers at the sealing or latching portions, which have to be eye-checked and make sure the appearance still complete as a whole. However, the mechanical structures and the serial numbers printed on the appearances of the locking tools mentioned above are very easy to be duplicated through modern arts, without leaving any evidence during the duplication. Since eye-checking is not able to differentiate the true and the false ones, such locking tools cannot achieve a satisfied protection for the transited goods. These conventional locking tools do not have electronic information implied thereon and become a severe bottle neck of the demands on globalized logistics and reduction of transportation cost.
Therefore, in the recent years after RFID (Radio Frequency Identification) chip development becoming more mature, some technologies regarding electronic locks (or electronic seal, simply called e-seal) that use unduplicated RFID chip and are incorporated with conventional mechanical seal have been patented. The electronic seal used on transportation containers may be classified as active electronic locks and passive electronic locks according to whether there exists an extra battery supplying power to the RFID chip. Active electronic lock has complicated internal structures and high manufacturing cost, and generally will be recycled for reuse accordingly. Since the active electronic lock has an extra battery supply power, warning signals may be sent automatically during unauthorized open operation or damages. As to the passive electronic lock, since the structure is relatively simple and there is no extra battery supplying extra power, the operating principle is to receive the electromagnetic power transmitted from external RFID readers, stimulate the RFID chip inside the passive electronic lock, and then use the received electromagnetic power to transmit identification data of RFID chip backwards as a responded electromagnetic signal, thereby facilitating a data exchanging operation.
As mentioned in the above paragraph, the method of applying the passive electronic seal (hereafter use electronic seal) for transportation containers is to combine the conventional mechanical seals and RFID chip, the announced patents as disclosed in Taiwan R.O.C. Patent No. 1285700, M328051 and 1292007, as well as China Patent No. CN2531066Y. The emphasized points are to use the general principle that the RFID chip must have a connecting line to connect with its antenna so that the RFID chip is capable of receiving and transmitting signals. The RFID chip and the antenna will be wrapped up separately in a pair of a bolt and a corresponding bolt pedestal of conventional mechanical seal, or disposed jointly in one of two ends of either the bolt or the bolt pedestal. When the bolt and the bolt pedestal is engaged and locked with each other on a door latch of a transportation container, the RFID chip and its antenna will be electrically connected and become a reliable reference by communicating with an external RFID reader to determine if the door latch is opened after being locked. However, the locking mechanism of such electronic container seal is to use a spring fastener inside the bolt pedestal to fasten a slot on the bolt. Such slot is easily to be smoothened by an external force or the spring fastener may be removed out by simple tools, and after these damage operations the bolt and the bolt pedestal can still be adhered tightly by glue or adhesive tape without evidences left on the appearances. In the past, such damage operation may be discovered by physically pulling and dragging of the investigation officers. Yet ever since the fast-passing policy of the customs clearance, investigation is simplified or negligence of investigation is occurred due to trusts on the RFID technology. Therefore, using the single connection between RFID chip and its antenna to transmit electronic signals as a locking mechanism is only a little bit advanced than using merely the conventional mechanical locks. In such circumstance, repeatedly using the electronic seal or using a simple conductive material as a bridge to connect with the RFID chip and its antenna becomes easily-unsecured connections without leaving any tracking record thereon. Thus, using this passive RFID electronic seal becomes a major security problem.
Therefore, how to improve the security during container transportation, how to enhance the identiability of container transportation and reduce the waste of manpower and time, becomes a major technical problems for the transportation industry deemed to be urgently resolved.